Providing lavatories on board airplanes is widely known. For examples of lavatories provided on board airplanes, see U.S. Pat. Nos. 5,150,863, issued Sep. 29, 1992, to Hozumi, 4,884,767, issued Dec. 5, 1989, to Shibata, 4,646,145, issued Feb. 24, 1987, to Alie, and 4,589,463, issued May 20, 1986, to Ryan. However, these fixed assembly lavatories are not concerned with the issues of doorway space utilization.
Doorway space utilization is the idea of making use of the floor areas and spaces immediately inboard of commercial airplane exit doors not needed during flight. The purpose of the present doorway space utilization concept is to increase the revenue generating capability of the commercial airplane. Doorway spaces are use for entry and departure from the airplane while on the ground and are required for emergency exit and attendant assist purposes. During flight, these spaces are largely unused.
By using doorway spaces during flight, there exists an opportunity to: (i) increase seat count, (ii) prevent seat (seat pan) loss, and (iii) add storage capacity. All of these opportunities can be used to increase the amount of revenue generated by the airplane thereby making the owner/operator of the airplane more profitable and the airplane more valuable to those commercial airplane customers.
Seat count gains are the most direct way to increase an airplane's value. Analysis of airline revenues and aircraft pricing indicates that each incremental seatpan added to an airplane of a given gross weight increases the value of the airplane at the time of sale by many hundreds of thousands of dollars. Avoiding the loss of a seatpan has the same impact on value.
Examples of apparatus providing increased space utilization on an airplane include an expandable volume lavatory disclosed in the aforementioned patent to Ryan and a convertible seat-bed disclosed in U.S. Pat. No. 3,898,704, issued Aug. 12, 1975, to Gallaher, etal. Also available for use on the McDonnell Douglas MD-11 commercial airplane is an accessible expandable lavatory for the physically impaired. When stowed, the lavatory is basically a conventionally sized module. When the need arises or on-demand, the lavatory can be expanded into the passenger doorway area to permit positioning of a wheelchair next to the toilet in the lavatory.
Increased storagle capacity can also be related in revenue or value terms. Most airlines would find additional storage capacity useful on their airplanes. This capacity might be used for providing additional services, such as duty-free sales, or might displace conventional monument storage off of revenue floorspace, like closet or galley trash volume. None of the patents disclosed above provide increased airplane storage capacity of the type afforded in the present invention.